The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => A7 & A10 Engine => Topic started by: Tone on 20.07. 2009 19:46
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Hi, I have taken off the timing cover to send the inner cover to Sean Hawker to have the oil seal done prior to fitting a belt drive.1st, the oil pump compartment was full of oil I don't think thats right? 2nd, there are 3 nuts to take off, also the worm drive gear (I think) is this part of the pump? what I mean is do you remove the left hand tread nuts and take off what looks like a spring,or does it all come off together with the pump?
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Tone, you remove the oil pump 3 nuts, remove the left hand locknut and tab washer and wind off the worm gear. The oil pump will come with it. Note the correct size spanner or socket for the locknut and worm is 25/32".
The compartment will be full of oil.
Don't lose the flat washer under the worm gear.
Trev.
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Thanks Trev, Odd size of spanner, thats why its mullered!!
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Funny about that size. I think, if my memory is not failing, that the swinging arm gearbox bolts and nuts are the same.
Trev.
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Trev, would that spanner size be Whitworth?
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Tone,
no, it is an AF size. Or SAE if you like.
Trev.
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Sorry Trev, Where did you buy a 25/23" socket from? I,m having trouble getting one, Tone.
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20 mm socket works just fine.
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I've bought 19/32", 21/32", 23/32", and 25/32" wrenches for my three BSAs. It's surprising how many nuts they fit perfectly, either by design or coincidence. 25/32" is 19.8 mm, so a 20 mm will be just a tad loose but likely will do fine.
I pick up odd wrenches at flea markets and swap meets. It's surprising how many nice Craftsman or Klein or Snap-On tools are lurking in the bottom of odd boxes along with the Oriental junk ...
Lannis
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25/32" is 19.8 mm
I could have done with borrowing your 25/32" wench/spanner this very evening Lannis. That bloomin nut holding the banjo on the back of the oil tank was awkward to get at. I was actually thinking that a 19.5mm spanner would have done it. My remedy? took the nut for a good filing down! *whistle*
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Hi Lannis and All,
Not wishing to upset you, I know the crank end nut is an oddball size,
but virtually all the nut sizes on BSA A7/10's are Whitworth sizes
with either whitworth or cycle thread forms
the only other odd thread besides BA on the electrics that I can think of at the moment
are the nuts on the back of the speedo, 0BA thread with a 3/16whit hex
here is a link to a comparison chart, there are loads on the net,
http://www.gomog.com/allmorgan/whitworth1.doc
A good source of good quality Whit spanners are army surplus stores, I bought some really good quality ones at the store near here
Regards
John O R